1. Field of the Invention
This invention relates to a sensor which when subject to motion or vibration adjusts its output accordingly.
2. Description of the Prior Art
Various types of sensors have been used to record events occurring at a selected location over time. These sensors could be anything from video cameras to infrared detectors. Typically, the sensors produce analog signals corresponding to the scene which they observe. The analog signals are digitized to create digital images of the scene. Those digital images can be stored in a memory, displayed on a screen or directed to a variety of processing systems which may either extract information from the image or modify the image in accordance with predetermined procedures.
One or more sensors may be mounted to a host platform. When several sensors are used their signals must often be combined to generate a useful image. In some situations sensors must be mounted on platforms which flex, vibrate or move in any direction. All such types of motion in any degree shall be hereinafter called movement. Platform movement can cripple efforts to combine signals from sensors that are mounted on the moving platform. For example, a 100.degree. per second motion would move scene data across 116 pixels if each detector's Instantaneous Field of View (IFOV) is 150 .mu.r and the integration time is 0.01 seconds. Vibration levels can reach 10 pixels, peak to peak on common aircraft platforms. The resulting loss of signal to noise ratio as well as spatial information is a major problem.
Intra-sensor alignment is important for tracking and clutter discrimination. Relating data to a common inertial reference frame is also important for "pointing" targeting systems accurately. For multiple sensors sensor-to-sensor alignment is important. Sensors must be maintained in relative alignment to one another or the signals from them must be corrected to account for any misalignment which occurs. Moreover, the signals from the sensors must be integrated and normalized in a relatively short time to account for overlaps in fields of view among the sensors, and movement of sensors resulting from vibration or movement of the platform on which the sensors have been mounted.
Consequently, there is a need for sensor which can detect and compensate for motion, flexure and vibration. Such sensors should also be either positioned or movable to cover a wide field-of-regard.